THE BITTER PIT "DISCOVERY.

Dominion, Volume 4, Issue 1131, 19 May 1911, Page 8

THE BITTER PIT "DISCOVERY.

FULLER PARTICULARS. The 'Sydney and Melbourne papers by last mail contain a good deal of interesting matter about the reported discovery by Dr. Jean White and Professor A. J. llivart of tho causo of bitter pit in .apples. The Melbourne "Age" reports that the Minister tor Customs announced on May 10 that a small committee had investigated statements made by Dr. White and evidence produced by him, and had reported that "tho question of an independent subsidised investigation may reasonably bo postponed for twelve months." In the meantime, it is proposed to defray the cost of a continuation of Dr. White's experiments in which tho expert officers of the States would assist' in supervising the experiments necessary "to disprove or prove the theory nov; put forward, which connects tho difeaso with the use of certain poisonous substances for the destruction of, codlin moth," In the course of ,1 paper on bitter pit. Dr. White said that tho investigation of the disease was undertaken about tho middle of last year. Tho field work was performed at Burnley Horticultural Gardens, by permission of tho principal, Mr. E. E. I'escnV-aud also by Professor Ewart in his , own orchard at Box Hill. The disease appeared somewhat suddenly during' tho lato. eighties and early nineties of last century in Australia, apparently shortly after the practice of spraying for codii:. , moth was first introduced. Tho idoo of tlio presence of lnicro-organ-:isms in connection with tho, disease was .now refuted by practically all investigators. That tho disease could not be transmitted by inoculation had been established. Observations niado during' tho field work at the Burnley Gardens suggested that. the disease was caused by the entranco of the poisonous substances .used as insecticides and sprayed over, the fruit. The pits could be artificially produced- by simply rubbing the surface of a fairly young apple with some strong 'poison. Observation was made by ProItessor. Ewart on his own orchard, Vihich .was divided into -halves, one half bcinj sprayed and tho other half being loft uneprayed. Whilst the majority of the trees in the sprayed portion possessed pit;ted apples, not a single specimen was. forthcoming from the unsprayed portion. Severely pruning a tree would render the fruit more concentrated, aud so more ■readily reached by the spray. The sapny varieties of fruit were more subject to tho lliscasc. Dr. White's theory has been generally loubtcd (according to the Australian files). Tho Victorian Minister of Agriculture (Mr. Graham) said that though he had never used the spray bitter pit had occurred in five or six different varieties of apples time and again, and all the prominent orchardists in ■ Victoria had had the same experience. Mr. Graham did not think tho fruitgrowers would approve, of ■ the postponement of Mr. M'Alpine's investigations. Discussing the matter, Mr. D. G. M'Alpino (who was recently asked to accept a four years' engagement by Fede- ' Tal and States' Governments at ,£IOOO a year to investigate the whole subject) stated: "Recently a new spot was brought ■ render.my notice. The injury was quits superficial, extending into the pulp only slightly, and in this respect differing from tho disease known as bitter pit, which is found throughout the flush as well as at tho surface. The superficial spotting of the fruit was suspected to.be duo to arsenical, poisoning,' and chemical analyses wore made'by Dr.. H. W. Wiley, chief of the. Bureau of Chemistry, who reported as follow*: —'It will be noticed that in most rases the diseased ekin contains more arsenic than the normal skin from the same apples. However, in some cases skin from the perfect apples, showing no spots at all, contained as much ois more arsenic than "was sometimes found on the spotted portion of tho diseased apples. The roPiilts indicate a connection between the diseased spots and arsenic content, but we do not consider it conclusive.' Both apples and pears grown in Victoria, with bitter pit well developed in the flesh, did not show the slightest trace of arsenic on analysis." -